I totally agree here - fandom average age will vary by fandom.

I count myself lucky and everyone I've found so far is cool with people no matter what their ages are, so it's never been a worry of mine.

Also, I kind of love large age differences because then there can be a sort of mentor-relationship going on. I have some friends who are 25 years older than I am, and have been great for talking about RL things I might not feel comfortable talking to my parents or aunts and uncles yet, and they have RL experience to go off of.

So I say don't worry. ♥